Fluid-pressure system.



PATENTED JULY 2, 1%?

W W015 MAW WVEIIEF Egan-15 (2 ar 0 1 IE; (Lg/aw; CDL' fmmrntgn iii compressed aiix WALTER J. RICHARDS, OF MILWAUKEE, WISCOXSIX.

FLUID-PRESSURE SYSTEM.

Specification of Letters Patent.

Patented July 53, 1907.

Application filed Oct be 6,1904. Serial No. 227,511.

Tdall 'UIIODL it may concern:

Be it known that I, WALTER .l'. RICHARDS, a citizen of the ['nited States. residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a certain new and useful Improvement in Fluid-Pressure Systemsoi which the following is a full, clear, concise, and exact description. reference being had to the accompanying drawings. forming part of this specification.

My invention relates to electrically driven fluid pumps, and particularly to the use of alternating currents for the purpose of supplying the necessaryenergy to the motor mains.

In a general way. the present invention is similar to an invention disclosed in my co-pending application ,Serial No. 161,085, filed July 2, 1903, in which, however, the motor is adapted for use in conjunction with a supply of direct current.

In accordance. with my present invention, I provide a pressure system supplied by a pump or compressor, the operation of the compressor being controlled in accordance with variations in the pressure in thesystem, whereby the pressure within the system is mainatain ed at or near a given constant pressure.

. My invention provides means whereby the supply of :7 trrent to the motonat starting controlled in such waythat the motor will not be subjected to an undue rush of current, which would either burn out the windings or require the motor to be of uneconomical design.

In addition to the provision of means for limiting the supply of current to the motor at starting, independently of the-load on the motor, this invention provides also a means for permitting the motor to start under practically no load conditions, the load being thrown upon the motor only after it has attained substantially its full normal speed.

The invention is diagrammatically illustrated in the accompanying drawing.

At 10 I have illustrated a storage reservoir or tank, from which the supply pipe ll leads to the devices which, in this instance, are intended'to be operated by I The tank is supplied with comi than the outer. ends or the contact fingers 6- 65 and 66, A i

pressed air by means of the compressor 12, which is driven by means of an alternating current motor 13. controlling switch 14 is connected by means of the pipe 15 with the reservoir 10 and serves to control the operationof the motor in accordance with variations in the pressure system. This switching device consists essentially of a bent tube 16, like that of a Bourdon pressure gage, which is connected by'mea-ns of the link 17 with a switch arm 18, this switch armmoving between the con tacts 19 and 20. At A I have shown a switching device, which, in mechanical construction, may be like that shown in my co-pending application, Serial No. 152,165, filed April 11, 1903.

In the diagram I have shown the insulated contacts 21, 22, 23 and 24, the contacts 21 and 22 being electrically connected by means of the connector clip 25, when brought into engagement therewith, and the contacts 23 and 24 being connected by means of the clip 26, the clips 25 and 26 operating concurrently in accordance with the movements of the core 27. The solenoids 28 and 29 cause the reciprocation of the core 27 either one way or the other, depending upon which solenoid is traversed by an electric current. The operation of this device will hereinafter be more fully explained.

At B is shown a main switch for connecting the apparatus of my invention with the alternating current mains 30, 31 and 32. The compressor comprises a cylinder 33. piston 34, its piston rod 35, the usual discharge valves 36 and 37, and suction valves 38 and 39.

The suction valves are provided with downwardly projeeting stems 40 and 41, these stems being engaged respectively by the levers 42 and 43, to the free ends of which are attached the cores 44 and 45, n'iovable with in the solenoids 46 and '47, respectively. The weight of the cores serves normally to maintain the suction valves unseated. as shown. Upon cnergization the solenoids cause the upward movement of their associated cores to permit the seating of the associated suction valves. The alternating current motor comprises primarywindings 50, 51 and 52. and secondary windings 53, 54 and 55, these wind being star-connected, as shown in the diagram. The association between these windings is of an inductive nature, as is well understood by those skilled in the art, one of the sets of windings being movable with respect to the other. The star-connected resistances 56. 57 and 58 are connected with the outer terminals of the secondary windings oi the motor, as shown.

At C there is a switching device adapted to control the resistances in their electrical association with the secondary winding of the motor. For the purpose of diagrammatic illustration lhave shown a series oi insulated contacts, 61 to 68, inclusive, all mounted upon a.

stationary shaft or support 70. These contacts are given somewhat different inclinations, as shown, coma 61, 62 and 63 having their outer ends in a lower position while the contact fingers 67 and 68 are slightly higher than either of the other sets. short-circuiting contact plate '71 is supported by means of the insulated and pivoted bars 72 and 7 an auxiliary contact plate 7 1 being mounted to oscillate with the contact plate 71. The movementoi these contact plates is controlled by .1. solenoid 7-5, into which the core T6 proj this core connecting by means of the cord 77 with the contactplate 7l. The drawing shows the contact plate 71 slightly above its normal position and in engagement with the contact fingers 61 to 63, inclusive. The upward movement of the contact plate 71 is retarded by the dashpct diagrammatically illustrated at 7 The operation of these devices may he described as iollowsz flssinning the main switch B to he closed and that the pr .:e in the reservoir 1.0 has been reduced to its minimum limit, the switch arm 18 brought into engagement with the Contact post 19, thereby closing circuit which may be traced as follows: from the main 32, through conductor 80, conductor Sl, solenoid contact post lil, switch arm 18, conductor o2, conductor 83, conductor 84, to the motor winding 52, to the i'leutrsl point, thence through winding 50 and conductor to the main 30. Current flowing through this circuit energizes the coil 28, causing a movement of the core 27 to the left, and electrically connecting the contacts 21 and 22 by means of the clip 25, and the contacts 23 and 24 by means of the-clip 26. The movements of this switching device A completes the closure oi the primary cir- Cuit of the motor, this circuit being traced from the main 30 through conductor 85: and coil 50 to the neutral point; ll'OKll main 31, through conductor 86, contact 21, connecting clip contact 2" conductor 87 and coil 51 to the neutral. point; and hour main 32 through conductor 80, contact 2%, connecting clip contact .23, conductor 8?, conductor 34, and coil 52, to the neutral point. Th e currents traversing these primary windings induce currents in the secondary coils 54 and 55, the secondary circuit being closed through the resistunces 5G, 57 and 58. On the initial closure of the switch A the resistances are included directly inlhe secondary circuit, the-switch blade 71 being in its lowest position and out of contact with all of the Contact lingers 61 to 66, inclusive. The actuation of the switch A also closes another circuit, which may be'traced' as follows: from the main 3], through conductor 86, contact 21, connecting clip 25, contact 22, conductor 88. solenoid 75, conductor 83, contact 23, connecting'clip 26, contact. 24 and conductor 80, to the main 32. The onergimtion of this coil causes an upward attraction of its core '7l'i,-Where' by the Contact plate 71 is drawn slowly upward. against the retarding influence of the dushpot 7 The cont-act plate 7]. first engages the three fing (ll, 2 and 63. The inner sections oi the resistances are thus short-circuited, cutting down thetotal resistance in the secondary circuit of the motor. As shown in this diagrammatic figure, the contact lingers are thin and flexible, so that the upward movement of the contact plate is not arrested by engagement with the first three contact fingers. The upward motion is continued, therefore, until engagement is made with the three contact fingers marked 64, 65 and (56. This connection serves to complete the short-circuit of the resistances 56, 57 and 58, whereby the secondary circuit of the motor is completed through circuits of almost no resistance whatever. As is well understood by those skilled in the art, the decrease of the resistance in the secondary circuit not only permits an increase of the flow of current in the secondary circuit but in the primary circuit also, but during the cutting out of the resistance in the secondary circuit the motor is increasing its speed of rotation, whereby the increasing electrical and magnetic reactions Within the motor serve to prevent the flow of excessive currents through the motor windings. As the core 7 6 continues its upward motion, the contact plate 74 is ultimately brought into engagement with the contact fingers 67 and 68, whereby the circuit is closed through the solenoids 4G and 47, thereby causing their energizntion and the upward attraction of their cores 44 ends-5 respectively. this movement of rho cores permitting the suction valves 38 and ill) to scan llicrcliy thnnvingdhe loud oi the compressor upon the motor and causing the (lischurge oi coiupi :ed air into ihc reservoir ll). it will be noted that during the pcriod in which llll. rcsistuucce are included in the secondary motor circuit and until these resistances urc cul. out oi the ('llClllll during which period the motor will have uituincd substantially its full norniul speed oi rotor ion. the suction vulycs are prevented from scoring whereby the motor ln'oiight to speed under practically no load conditions, the air being alternately drawn into the compressor cylind c1 and expelled thercironi by Way of the ports of the suction valves. After the compressor l discharged into the reservoir for u sullicient length of tune to bring the pres sure to its maximumlimit, the switch arm 1% 01' the governor is brought into electrical conuocr ion with the corn tact 20, rrherehy a circuit closed through the solenoid 2b, this circuit lacing traced as follows: from the main 31, to contact 2l, connecting clip 25, contact 22, thence by way 01' the conductor 90 through the coil 29, conductor-91, contact post 20, switch arm 18, conductor 32, contact -3, connecting clip 26, contact 24, and coin ductor 80, back to the main The onergizution of this coil 29 causes it movement of the core 27 to the right, thereby lilrculiing the ele rtricul connection between the (Oiltucts or the switching device A. This opens the circuits which have heretofore been traced. The weight of the cores 44 and -15 returns their suction ivcs to their positions as shown the diuwing in which they may not seat themselves upon the operation of the compressor, and the weight of the movable switch members of the switching device C returns the Contact plates 71 and 74 to their normal position in which the short-circuits about the resistances 5G. 57 and 58 are reni red. The apparatus is thus returned to its normal condition, ulnareurwnlhe decrease of pressure in'lhe sy tem to its minimum limit causes :1 repetition of the operation already described.

it will bc'understood that this description and the accompanying drawing show only in outline the actual mechanical structures which in practice would be employed to carry out my invention Furthermore, I do not wish to be limited to the precise construction set iorth, but

What I claim as new and desire to secure by Letters Patent is set forth in the following claims 1. In combination, an alternating current motor, having .1 primary circuit and 21 secondary circuit, :1 resistance normally included in the seeondury circuit, Sl0'\\''l(?llll electromagnetic, mechanism adapted upon energizution gradually to reduce the'-resistuuce in said secondary circuit, a switch for closing the primary circuit. and menus associated with said switch for causing the energizution of said electromagnetic mechanism upon the closure of the primary circuit.

2 In combination, on ulternatin' current motor, having :1 primary circuit and a secondary circuit, a resistance normally included in the secondary circuit, $low ucting normally included in the secondary circuit, electromagnetic mechanism adopted upon energization to reduce the resistance in said secondary circuit, aretarding device associated with said electromagnetic mechanism, a switchtor closing the primary circuit, and meansfor causing the encrgization of said electromagnetic mechanism upon the closure of-the primary circuit.

l. In combination, an alternating current motor, having a primary circuit and a secondary circuit, current-restricting means associated with the secondary circuit of said motor, slow-acting electromagnetic mechanism adapted upon cnergization to remove the restriction to the flow of current in the secondary circuit of said motor, a switch for closing the primary circuit, andmeans for causing the energization of said electromagnetic mechanism upon the closure of the primary circuit.

5. In combination, a fluid pump, an alternating current motor for driving said pump, said motor having primary and secondary circuits, slowacting electromagnetic mechanism adapted upon energization to gradually reduce the resistance of the secondary circuit of the motor. and means for causing the energization of said electromagnetic mechanism upon closure of the primary circuit.

6. In combination, a fluid pump. a pressure system supplied thereby. an alternating current motor for driving said pump. said motor having primary and secondary circuits, a resistance normally included inthe secondary circuit. a switch governed by the pressure in the system for controlling the primary circuit of the motor, and automatic means for cutting the resistance out of the secondary circuit of the motor after the closure of the primary cir cui't.

T. In comlduation, a fluid pump, a pressure system sup plied therebya an alternating current motor for driving said pump. said motor having primary and secondary circuits. current-restricting means associated with the sec oudary circuit. a switch governed by the pressure in said. system for controlling the primary circuit of the motor, and automatic electromagnetic means associated with said switch for removing the restriction to the flow of current in the secondary motor after the closure of the primary circuit.

S. in combination, a fluid pump. an alternating current motor ha 'ingr "rimary and secondary circuits, said pump being driven d motor. a res .uuce normally included in the secondary circuit. automatic electromagnetic switching mechanism for cutting out the resistance in said secondary circuit. means for retarding the motion of said electromagnetic mechanism. and means for closing the circuit through said electromagnetic mechanism upon the closure of the primary circuit.

9. In combination. a fluid pump, a pressure system supplied thereby. an alternating current motor for driving said pump. said motor having primary and secondary circuits. a switch governed by the pressure in aid vstcm for closing-the primary circuit of said motor. a resistance included in the secondary circuit ct said motor, switching means for cutting the resistance out of said secondary cit cuit, automatic electromagnetic mechanism for operating said switching means. a retarding device associated with said auiomatic electromagnetic niechauis n and means as sociatcd with the first said switch to closing the circuit through said electromagnetic mechanism upon the closure oi the primary circuit.

1 In comhinai'ion. au alternating current motor. an air compressor driven thereby. a pneumatic pressure system supplied hy said compressor. means controlled by the pressure in viid system to close the motor circuit upou adecrease the pressure in the -rem to a minimum limit ill and to open the motor circuit upon an increase in such pr sure to a maximum limit. a resistance in the secondary car at of said motor. a path oi high conductivil' includin" a normally open switch connected in shunt of said l'eSiStance. clectron'ingnetic means a iciated with the motor .ptcd upon cncr; zatlou to close said switch, mechanism rving normally to maintain the valves of said (:ollipl'cssol' in an open condition. and means for actuating said mechanism to allow closure ol' saitl valves when said resistance has been cut out of circuit.

11. In combination. an air compressor.

a pneumatic pressure system supplied thereby. an alternating current electric motor for driving said compressor. said motor having primary and secondary circuits, means controlled by.

the pressure in said system to close the motocclrcultupon a decrease in pressure in the system to a minimum limit and to open the motor circuit upon an increase in said pressure to a maximum limit, a resistance in the secondary circuit of the motor, a path of high conductivity including a normally open switch connected in the shunt of said resistance, and slow-acting electromagnetic mechanism included in the motor circuit adapted upon energizatlon to close said switch.

12. In combination, an air compressor, a pneumatic pressure system supplied by said compressor. an alternating current motor for driving said compressor, said motor having primary and secondary windings, means controlled by the pressure in said system to close the motor circuit upon a decrease in the pressure in the system to a minimum limit and to open the motor circuit upon an increase in said pressure to a. maximum limit, a'resistance in the secondary circuit of the motor, a path of high conductivity including a normally open switch connected in shunt vof said resistance. electromagnetic mechanism in a circuit controlled by the motor-controlling switch and adapted upon energizatlon to close said normally open switch connected in shunt of said resistance, a dashpot adapted to control and .retard the motion of said electrw. magnetic mechanism, means for maintaining the suction valves of the compressor in a normally open condition, and electromagnetic means for automatically permitting the closure of said suction valves when said resistance has been cut out of circuit.

' 13. In combination, an air compressor, an alternating current motor for intermittently driving said compressor, said motor having primary and secondary windings, an automatic rheostat for restricting the flow of current in the secondary winding of said motor independently of the load on said motor, and automatic means for increasing the load on said motor upon the removal of the restriction in the flow of current by said automatic rheostat.

14. In combination, a fluid pump. an alternating current motor for intermittently driving said pump, said. motor having primary and secondary circuits, an automatic rheostat for restricting the starting current traversing the secondary circuit of said motor independently of the load on said motor. and automatic electromagnetic 'means for increasing the load on said compressor upon the removal of the restrictionlu'current flowing in said secondary circuit.

15. Incombination. an air compressor, an alternating current electric motor for intermittently driving said compressor, said motor having a primary and a secondary circuit, an automatic rheostat for restricting the starting current in said secondary circuit, and automatic electr0- magnetic means electrically connected with the motor circuit for increasing the load on said compressor upon the removal of the restriction to the current in the secondary circuit.

16. In combination, a fluid pump, a pressure system supplied thereby, an alternating current motor for driving said pump. said motor having a primary and a secondary circuit. means controlled by the-pressure in the system to close the primary circuit upon a decrease in the pressure in said systemto a minimum limit and to open said primary circuit upon an increase in said pressure to a maximum limit. an automatic rheostat for restricting the starting current in the secondary circuit of said motor. and automatic electromagnetic mechanism associated with the primary circuit of said motor for increasing theload on said compressor upon'the removal of the restriction to the current in the secondary circuit of said motor.

17. In combination, a fluid pump. a pressure system supplied thereby. an alternating current motor for driving said pump. said motor having a primary circuit and a secondary circuit. 'means controlled by the pressure in system to close the primary circuit of said motor upon a decrease in the pressure in said system to a minimum limit and to open the primary circuit of said motor upon an incrcaseiu said pr matic rhcostat for restricting the starting current flowing in the secondary circuit of said motor independently of the load on said motor. and automatic electromagnetic means adapted for electrical connection with the motor circuit to ssure to a maximum limit, an auto-.

interval motor.

in combination, a, fluid pump, a supplied thereby, an a'ltern ting current mo or lor Inittently driving said pump, said motor having :1 primary and a secondary circuit, an automatic rheostat for r ricting the starting current in the secondary circuit or said motor independently of the load on said motor, and automatic means acting independently of the pressure in said system to increase the load in. saidmotor upon the removal of the restriction in the supply of current by said aut matic rheoslat.

.19. In combination, a fluid pump, a pressure system supplied thereby, an alternating current motor for driving; said pump, said motor having primary and secondary windings, mean: controlled by the pressure in said system to close the primary circuit of the motor upon a decrease in the pr sure in said system to a minimum limit and to open saidmotor circuit upon an increase in said pre sure to a maximum limit, an automatic rheos'tat for restricting the starting current supplied tosaid motor independently of the load on said motor, and automatic electromagneti con trolled means serving normally to maintain the val es of said pump in an inoperative condition but. upon the removal of the restriction in the supply of energy to motor to permit the operation of said valvesv 20. in combination, an alternating current motor hav ing a secondary circuit, a fluid pump driven thereby, said pump having valves normally maintained in an inoperative condition, a pressure systcm supplied by said pump, switcl: ing;- means governed by the pressure in said. system to coutrol the supply of energy to the motor. means fox-restrict.

in; the fiow of current in the secondarycircuit 01 said motor at starting". and electromagnetic means automatically actuated to permit the operation of said valves upon the removal of the restriction to the fioyv of current in said motor circuit.

21. In combination. a fluid pump having suction valves normally maintained in an open condition, an alteruatii'rg current motor for driving said pump, said motor having a primary and a secondary circuit, a pressure system sup plied by said pump. switching means controlled by the pressure in said system to control the primary motor circult. means for restricting the flow of current in the secondary circuit of the motor at starting, means for auto matically permitting the operation of said valves, and

-means for removing the restriction of the supply of current to said motor after the lapse of a suitable interval after the initial closure of the motor circuit.

32 In combination. a fluid pump, an alternating current motor for driving said pump, said motor having primary and secondary circuits, switching means for controlling the supply of current to said motor, means serving nor mally to prevent the operation of the pump valves, a resistance normally included in the secondary circuit of said inoto slow acting electromagnetic mechanism adapted to short circuit said resistance after the lapse of a suitable interval after the closure of the motor circuit, and electronurgnetic mechanism associated with said pumpvalves and adapted to incapacitate said preventive means after the initial supply of current to said motor.

23. In combination,-an alternating current electric motor having a primary circuit and a secondary circuit, a fluid pump driven thereby, switching means controlling the circuit through-said motor. a resistance normally in eluded in the secondary circuit of the motor. automatic means for gradually disconnecting said resistance from the secondary circuit upon the closure of the primary circuit,-means serving normal y to prevent the operation of the valves of thecompressor, electromagnetic mechanism serving when energized to permit the operation of said valves, and means for causing the energization of said electromagnetic mechanism after said resis .ance has been cut out of the secondary circuit of the motor.

'24. in combination, an alternating current motor having a primary circuit a a secondary circuit, an air pressor driven thereby, a pneumatic pl't-SSllP supplied by said compressor, switching mechanism gov erncd by the pressure in Edit system to cause the closure of the primary circuit of said motor upon a decrease in the pressure ln said system. to a minimum limit and to C(lllla break in the primary ircu t, of the motor upon an the rcuit resi tances normally included ii? the oudary motor circuit :1 the closure or p-in.l circuit of the motor, m an icrvins; normally to maintain an opening in each end or the compressor cylinder. and electromagnetic hiechanlsm said ;tances have been cut out 01' the secondary n-cuiL to will st the osure oi the openings in the ends of the cempresrnr cy mder.

25. In combination. a fluid pump, a pressure the cults, a resistance normally included in the second: circuit, an electromagnetic s vi governed by the pres-- sure in the system it controlli the p imary rircux of the motor, and ;,1utom:1lic means 101' cutting the resistance out of the secondary circuit upon the closure ol the 1 l mary cir by said electromagnetic mechanism.

26. in combination, an alternating current motor, a pump driven thereby, a pneumatic pressure system sup plied by said pump, means controlled by the pre said sy the motor cii tilt upon a decrease in the pro 2 in the system to a minimum limit and to-opcn the motor circuit upon an increase in the pressure to a n1 'num limit. :1 r tance in the secondary circuit 0. said motor, switching mechanism connected with said rcshtaucc, electromagnetic mechanism [or controlli'. .lid switching; mechanism. aid electromagnetic mechanism being actuated upon connection 01' the primary in circuit. valves for said pump, preventative means .ervinr' normally to pre ent oper lion of said valves, electron lgnetic menus controlling said preventative means, and a, circuit for said clectroims'nctic mechanism closed by said switching mechanism n r the re; stance has been removed from the secondary circuit. whereby said valves bccon'ie tmeratlvc.

27, In combination, an alternating current 11. Apr having primary and secondary circuits, of a pump driven by motor, an electromagnetic switch controlled by the pr sure in the system suppllcd by said pump for Connecting the primary of said motor in circuit, a second electromagnetic switch controlled by said first electromagnetic switch, a resistance normally included in the secondary circuit. of the motor, contacts for said'sccond electromagnetic switch connected with said resistance. means for causing successive actuation of said contacts, whereby said 1' istancc is gradually removed from circuit, normally inoperative valves for the pump, electromagnetic mechauisln controlling said valves, and a circuit including electrcunng'nctic means adapted to be closed by said second electromagnetic switch to render said valves operative after said resistance has all been removed from circuit.

28. In combination, a fluid pump, an alternating current motor for driving said pump, said lllolor having primary and secondary circuits, switching means for controlling; the supply of current to said motor, means serving; normally to prevent effective operation of the pump, a rcsistance normally included in the secondary circuit 01? said motor, electromagnetic mechanism adapted to gradually we in remove said resistance from circuit, and electromagnetic mechanism actuated by said slow-acting electromagnetic mechanism to render the pump ellective after said resistance has been removed from circuit.

29. in combination, a fluid pump, an alternating current motor for driving said pump, said motor having; primary and secondary circuits, slouwicling electromagnetic mechanism adapted upon ene nation to control the cur rent in the secondary circuit of the motor, and electromagnetic means for causing the energization of said elcc tromagnc'tic mechanism upon closure of the primary cir- Cult.

In witness whereof. I hereunto subscribe my name this third (lay or October A. IL, 1904..

\VALQlClZ I. RICHARDS. 

